ES2282166T3 - USE OF AN ADHESIVE TAPE WITH WRAPPING CABLE TAPE. - Google Patents

Abstract

Use of an adhesive tape as a wrapping tape for cables, so that the cables have a PVC-free coating, which includes a PVC-free support, to which at least one side is applied a pressure sensitive adhesive composition based on acrylate , so that the adhesive tape that sticks to the cables, at a temperature of at least 100 ° C and for at least 240 hours, does not damage the coating in any way.

Description

Using an adhesive tape as a wrapping tape of cables.

The present invention relates to the use of a Adhesive tape such as cable wrapping tape where the wires They have a PVC-free coating.

The electrical and electromechanical components as well as the envelopes of the electrical conduits consist many times of polymeric substances, where the chloride of Polyvinyl (PVC) is equivalent to the most important plastic, because basically its availability as well as its excellent Insulation properties and as raw material.

For the electrical and mechanical protection of this type of cables formerly developed self-adhesive tapes, such as those that are generally used for protection and insulation as well as the wrap of cables and components electric

Self-adhesive tapes allow manufacturing a durable bond without due to tape interactions Adhesive and cable wrap will damage the cable. In Particularly additives in plasticized PVC tend to migration and therefore require certain adhesive tapes.

Because of this, some tapes have been manufactured adhesives with a support of PVC sheets; on the one hand due to its mechanical properties, on the other due to minimal problems of compatibility since at least the support and base of Adhesion are of the same material.

For special applications such as winding of sections of pipes or cable harnesses in the devices domestic machines, and in particular vehicles has spread a lot the use of self-adhesive tapes that have a textile support, for example, a polyester or viscose fabric.

Within the framework of discussions about the environmental tolerance of PVC there is a tendency to replace this material by alternatives. Auxiliary parts and components electrical as well as copper wire cladding has been reinforced with other synthetic materials, so that it they use fluorinated polymers and thermoplastic elastomers such as Amitel® (DSM Engineering Plastics) or Hytrel® (DuPont), preferably polyester synthetic material in case of higher requirements

For the cost sensitive materials sector with minimum requirements in terms of temperature are used a lot of polyolefin materials, particularly since thanks to the metallocene technology the profile of mechanical properties similar to those of soft PVC, so that the polyolefins have outstanding insulating actions due to its chemical composition as carbon hydrocarbons cigars

Also for cable harnesses in vehicles it is given The trend of this type of PVC-free pipes while components such as plug-in connections, switches, tubes striated etc. They are preferably manufactured from materials PVC free.

The components or sections of pipes electrical wraps that are wrapped with self-adhesive tapes must ensure a safe operating capacity throughout the product life period, such as that of a vehicle. When choosing unsuitable adhesive tapes an intolerance can occur during the life of the product, which leads to damage to the cable up to extreme fragility - corrosion and short circuits with danger of failure of the entire electrical / electronic part would be possible consequences. In particular in vehicles such as coaches or trucks loading there is a high degree of tolerance requirement; at passenger space maximum temperatures of up to 80ºC, in the motor zone temperatures even superior.

That's why for the tape application sector a long-term test of cables has been achieved more than 3000 hours, for example, according to the FORD specification S95 GG 14K 024 BA, as standard exam - cable harnesses test will be stored at test temperatures and after a period set time, basically every 500 hours, will be placed around a mandrel with a defined diameter and then damage caused will be examined; this test takes place during a period of 3000 hours. Together with an opinion purely visual also takes place an electrical insulation test. The test temperatures are governed by the fields of application of the cable harnesses and reach 90ºC in the case of fabric to be used in passenger areas according to FORD S95 GG 14K 024 BA. For applications in the area of the engine will be required temperatures of 125ºC and even higher.

For this type of winding applications of cables are known adhesive tapes with a tape-shaped support fabric or fleece base, in which the fabric tapes are they have known for a long time and the ribbons with a fleece support are have been described in DE 94 01 037 U1. As an adhesive coating, preferably use sensitive self-adhesive coatings under pressure

DE 44 42 092 C1 describes an adhesive tape a fleece base that is coated on the reverse side of the support. DE 44 42 093 C1 is also based on the use of a fleece as a support for an adhesive tape. Here is described a Transverse fiber fleece reinforced by forming Fleece fiber meshes, that is a fleece known by the expert under the name of Malivlies. DE 44 42 507 C1 makes reference also to an adhesive tape for the wrapping of cables that is based on the so-called fleeces of many folds

From DE 195 23 494 C2 the use of a adhesive tape with a support based on fleece material for the wiring harness, which is coated with an adhesive by a side. In the case of the fleece that is used according to the invention is a spinning polypropylene fleece that thermally fixed with the help of a calender and marked, so that the embossing or embossing cylinder has a surface of 10 to 30%, preferably 19%.

The DE 298 04 431 U1 also reports the use of an adhesive tape with a fleece support for the wiring harness, where the fleece to spin Proposed is polyester.

From DE 298 19 014 U1 tapes are known adhesives based on a solidified fleece with air jets and / or Water. The inconvenience of these supports, despite this compacted, is that by this technique you cannot exclude a stretched each of the long fibers and the negative influence of the technical properties of adhesion. In case of a very solidified solidification of the support can not get other important properties for cable ties in cars.

In WO 99/24518 A1 a tape has been described adhesive, in which the support material is a fleece, which only  by the specific selection of fibers or filaments with a fineness greater than 15 as well as by an extruded layer of sheets is Suitable for the use of adhesive tapes. The inconvenience of its use it is not only the additional coating of the extrusion but the limitation of a very thick fiber based material. This results in a coarse fleece in which we miss the typical soft tissue character. In the textile industry there is a usual unit from France which is the denier that measures the quantitative value (fineness) of the threads. This unit is obtained of the equation:

Value quantitative = \ frac {Mass \ of \ thread} {Length \ of \ thread}

where a thread has the value of a denier when the weight of a 9000 m length is 1 g, corresponding to 1g / 1000m = 9 den. (Compare Römpp Lexikon Chemie - version 2.0, Stuttgart / New York, Georg Thieme Verlag 1999).

By replacing PVC with polyolefins, shows that the self-adhesive tapes used so far present problems with long-term tolerance. The breadth of the lesions appeared range from slight cracks in the cable sheaths due to cracking up to total breakdown by component breakage and cable wrap after a long storage period.

The good general compatibility of adhesive tapes with silicone adhesive compositions with almost all the synthetic substances that exist in the field electric, but adhesive tapes with silicone compositions they find few applications due to high costs and a Low availability In addition silicone products are avoided in the automobile sector because of the possibility of potential risk in lacquers (repairs) as well as in electronics.

The invention has the task of creating a Adhesive tape to be used as wrapping tape for cables, in which the cables will have a PVC-free coating, it is say one of polyester or polyolefins. The adhesive tape should be in direct contact and adhere without creating disorders in the wrapping A task of the invention is to eliminate The disadvantages of current technology.

To solve this task the invention proposes the use of an adhesive tape as a wrapping tape for cables, so that the cables have a PVC-free coating that include a PVC-free support that at least on one side has applied a pressure sensitive adhesive composition based on acrylate, so that the adhesive tape adheres to the wires to a temperature of at least 100 ° C and for at least 240 hours and not damages the lining.

In a preferred version the adhesive composition it can be pure acrylate, as a compound and / or as a mixture of a solution, as an aqueous system or as a melt.

By compound is meant mixtures of polymers already prepared and the corresponding additives that are necessary for the manufacture of finished products. The mixtures are mixtures of polymers.

For tolerance between free cables of PVC and the components as well as the adhesive tape has a decisive importance the adhesive composition. Through contact Direct migration processes can lead to alterations of the composition of the synthetic material and therefore of its properties: this serves both the adhesive composition and for its technical adhesion properties as in particular for plastic cable sheathing and mechanical properties and electric.

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The use of an adhesive tape with a adhesive composition based on acrylate melt meets especially the task of the invention. The free systems of solvent based on an acrylate melt such as those can be used prominently as described in EP 621 326 or also in EP 937 761 and are marketed for example by BASF under the name acResin UV®.

The compositions are especially suitable adhesives having a K value of at least 20, in particular higher of 30, which is measured respectively in a 1% solution in toluene at 25 ° C. The K value is determined in particular analogously to DIN 53 726

Said adhesive compositions will be obtained by example by concentrating a solution of a mass that it has some properties indicated above with respect to a System made like a molten metal.

The concentration can occur in some boilers equipped for it or in extruders, in particular prefers an extruder for degassing.

Preferred adhesive compositions are show for example in DE 43 13 008 A1. In an intermediate stage The solvent is completely extracted from the acrylate compositions manufactured in this way.

In addition, if necessary, others can be separated easily volatile components. After coating with the dough fused these compositions have a low proportion in volatile components Therefore you can accept all monomers / formulas claimed in the patent above indicated. Another advantage of the compositions described in the patent is that they have a high value and therefore a weight high molecular The expert knows that systems with molecular weights elevated can be crosslinked effectively. So it decreases the percentage in volatile components.

The solution of the composition contains, in a very appropriate form according to the invention, a 5-80% by weight, in particular a 30-70% by weight of solvent.

Preferably solvents will be used common in trade, low temperature hydrocarbons of boiling, ketones, alcohols and / or esters.

Preferably extruders of a screw, with two screws or with several screws with one, two or Several degassing units.

The adhesive composition can be crosslinkable. by chemical or thermal treatment, in particular by chemical ray treatment. The adhesive composition based on molten acrylate metal can be crosslinked by radiation Chemistry preferably with UV rays. Other types of crosslinking Also possible are, for example, the cross-linking by rays of electrons

In a prominent version of the invention, they add to the adhesive composition based on acrylate molten metal  substances that are activated by chemical and / or chemical rays - and / or thermally and / or polymerize in it, being treated in particular of photoinitiators, benzoin derivatives. As examples of this and Without limitation, benzoin acrylate or benzoin methacrylate, the ester of acrylic or methacrylic acid. These types of benzoin derivatives are described in EP 0 578 151 TO.

In a particularly preferred version, use as copolymerized compositions of self-adhesive (meth) acrylic acid and its esters with 1-25 atoms of C, maleic, fumaric and / or itaconic acid and / or its esters, (meth) substituted acrylamides, maleic acid anhydride and others vinyl compounds such as vinyl esters, in particular the vinyl acetate, vinyl alcohols and / or vinyl ethers.

The residual solvent content should be 1% by weight.

As support materials for the adhesive tape flat forms without PVC according to the invention are used to get PVC-free compounds after winding manufacturing protective or insulation. This is how tissues are used, genres of knit, fleeces, sheets, paper, felt, foams and coextruded as supports

Instead of soft PVC sheets are chosen preferably sheets capable of stretching, which fit sticking with plastics such as polyolefins or others textile materials as support.

Among the textile support materials are known Knits or knitwear based on natural fibers such as cotton or based on synthetic fibers such as polyester, polyamide, polyethylene, polypropylene, viscose, among others; the most different fleece brackets can also be used such as wetted fleeces, fleeces reinforced by water jets or thermally reinforced fleeces with or without pressure, yarn fleeces or needles, fleeces for knitting like Maliwatt or Malivlies, provided they are made of the appropriate fibers or filaments. In addition they can also be used felt, spongy material as well as other materials Support, PVC free.

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The previously reinforced fleeces are they will manufacture, for example, on sewing machines of the type "Malivlies" of the company Kart Meyer, currently Malimo, and they can acquire in companies such as Naue Faser Technik and Techtex GMBH. A Malivlies is characterized in that a transverse fiber fleece is strengthens by the formation of mesh based on fleece fibers.

As a support, a fleece of the type can be used Kunit or a Multiknit fleece. A Kunit fleece is characterized because of the treatment of a fiber-oriented fleece Longitudinally, a fabric with meshes on one side results and in the other a network of meshes or folds of fibers, but neither previously reinforced threads or fabrics. This type of fleece has also manufactured for example in sewing machines of the type "Kunitvlies" of the company Kart Mayer. Another feature The highlight of this fleece is that it can absorb forces of high traction longitudinally as fiber fleece longitudinal. Compared to Kunit fleece, a fleece Multiknit is characterized in that the fleece undergoes reinforcement through the puncture on both sides with needles both on the upper side as inferior.

Finally, the fleeces are also suitable to sew as a starting product, to create an adhesive tape according to the invention. A fleece for sewing is formed by a fleece material with a multitude of seams that run in parallel to each other. These seams are formed by sewing of textile fibers that intersect. For this type of fleece know sewing machines of the "Maliwatt" type of the company Kart Mayer, currently Malimo.

As starting materials for the supports textiles are provided in particular polyester fibers, of polypropylene, viscose or cotton. But the present invention does not It is limited to the mentioned materials but can be used a multitude of other fibers for the manufacture of fleece.

The basic fibers of the fleece consist preferably of regenerated polyester fibers or new fibers Of polyester. Fibers with a fiber length between 10 and 100 mm as well as a fiber thickness of 1.5 to 10 dtex.

A particularly appropriate application of the Adhesive tape according to the invention is the use as tape cable enclosure where the cables have a coating PVC free.

Under the concept of "cable" is understood in addition to the usual cables the plug-in connections, fluted switches or tubes and the like, which are applied in the Cable harness sector.

As PVC-free cable liners, they can be employ those based on thermoplastic elastomers, polymers of fluorine and polyolefins, as well as other PVC-free plastics. How examples that are not exclusive but that are used prominently are mention here the polypropylenes, copolymerized from PP- / PE or PP- / PE compounds as well as cross-linked polyethylenes.

Acrylate molten metals can be apply in multiple ways on the mentioned supports. further of the standard application method as direct base coating of nozzles, on rollers among other things, methods are preferred of transfer as indicated in DE 43 2 748 C2 in what It refers to the open structure of textile supports. In they the adhesive composition is initially applied on a canvas or woven tape with a non-stick coating and then in a paste coating station - if it is accurate using pressure and temperature to improve anchoring of the composition on the support material.

The desired technical adhesion properties As the strength of adhesion, stickiness and cohesion can be control in a certain proportion by crosslinking by chemical rays and adapt to the requirements. The winding of support material in large bullets is equivalent to the end of the own coating process

The adhesive tapes according to the invention which they can be manufactured by cutting or thundering the large bullets in the Desired dimensions can be chosen for cable wrap with a PVC-free coating, so that in one of the Main applications for manufacturing cable harnesses in vehicles are wrapped a multitude of individual cables by the roll of the whole mallet to give a branch. Enough Adhesion of the adhesive tape to the cable sheaths as well as on the back of the support itself are important properties that you must present the adhesive tape so that the envelope of the mallet cables last.

This requires adhesive forces, in part greater than 1 N / cm, if necessary greater than 2 N / cm, adhesive tape applications of the order of more than 15 g / m2 in case of a plain sheet support, greater than 25 g / m2 for textile supports, preferably 50 to 200 g / m2, according to The nature of textile support.

Cable harnesses wrapped with tapes adhesives according to the invention will undergo tests standardized, mostly found in the standards specials of the manufacturer of automobiles or electrical appliances - for tolerance control, the called "3000 hour test", for example, according to FORD S95GG 14K024 BA, as a long-term test.

This test is performed at elevated temperature for 10 days as a quick short-term test.

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According to the invention the adhesive tape does not produce any lesion in the lining when the cables are attached to a temperature of 100ºC minimum and for a period of time of 240 hours minimum. The duration of 480h is preferred, ie 24 days, during which no disorder is observed.

When the adhesive tape adheres on applications at a higher temperature, the demands increase. In  particularly if the temperature of the adhesive tape / cable assembly is greater than 125 ° C, preferably greater than 150 ° C.

In the rapid tests mentioned above 20 to 25º higher test temperatures will be chosen than temperatures that really appear in the adhesion, to exclude definitely subsequent damage to the coating. For the 3000h / 125ºC adaptation stages rapid tests take place at 150 ° C for a minimum of 10 days.

While the adhesive tapes are based predominantly in synthetic rubber compositions as well as natural rubber prove to be problematic in many cases in as for tolerance, with the self-adhesive tape according to the Invention a considerable improvement is achieved.

In addition to the improvements in compatibility the self-adhesive tapes according to the invention with a composition Acrylate adhesive offer another potential against most adhesive tapes that are used to date. By means of the Polyacrylate polymer choice, which is understood without large proportions of mixing components such as resins, plasticizers etc. and whose cohesion increases decisively through crosslinking, an improvement in resistance to temperature both in terms of maximum load and permanent load against rubber adhesive compositions natural and synthetic

The high temperature resistance of the adhesive composition is given even on the entire adhesive tape if it Choose the right support.

In particular in a combination of the adhesive composition mentioned with a polyester support, a plastic, which is known for good temperature resistance and Applies in the sector of adhesive tapes for devices electrical up to even class B temperature (130ºC load permanent), in isolated cases even class F (155ºC load permanent), the requirements of adhesive tapes of high resistance

Next the tape should be described adhesive according to the invention with the help of examples without the invention is limited to them.

Example one

On a textile support of the type Fleece-thread-stitched gender Maliwatt (80 g / m2, fineness 22, black, thickness approx. 0.3 mm) is applied by means of a nozzle coating an adhesive composition UV crosslinkable acrylate-molten metal Acronal® DS 3458 type at 50 m / min. The temperature load of support is reduced by means of a back pressure cylinder cooled. The application of the composition is approximately 65 g / m2. An adequate crosslinking is achieved before rolled by irradiation with a UV installation, It works with 6 Hg lamps at medium pressure at 120 W / cm.

Example 2

In the same fleece support as in the example 1 are transferred onto a nozzle of rods that roll to a speed of 10 m / min approximately 50 g / m2 thereof adhesive composition by means of a canvas tape, so that to improve the resistance between the support and the layer of adhesive composition in the bonding station a 8 bar pressure as well as a roller temperature of back pressure of approximately 70 to 80 ° C. The temperature of Melting of the adhesive composition is about 100 ° C. The Crosslinking is performed as described in Example 1, but the ejector power adapts according to the speed of lower coating.

Both samples are separated by rolls in front to conventional 10 lfm adhesive tape rolls and it They analyze their properties.

With adhesion forces to steel> 2.5 N / cm as well as on the reverse side of> 3.5 N / cm both samples meet safely the requirements for cable winding tapes (the Measurement of adhesive forces is carried out according to standards international at 180º at a traction speed of 300 mm / min)

For the study of compatibility is done reference to the test method described which, for example, is routinely employed by car manufacturers as Renault, Peugeot, etc.

The test cable harnesses are stored for 240 hours at 100 ° C or for 240 hours at 150 ° C.

For the manufacture of samples they are wrapped test leads (preferred sections of 0.35 or 0.75 mm2) of different manufacturers with polyolefin based coatings with Adhesive tape; after storage the tape is removed adhesive, the cable bends over itself (very large effort due to a narrow bending radius) and it is observed if they exist alterations and a visual opinion on embrittlement is made and crack formation as well as a discharge stress test with 1 kV for 1 minute.

The results displayed in the table serve for adhesive tapes according to example 1 and 2 based on a adhesive composition of acrylate-molten metal resin type ac.

As a comparative example a tape is shown Standard adhesive known for wrapping PVC coated cables to base of a natural rubber adhesive composition.

The test serves as passed (evaluation: i.O.) when after 240 hours (corresponding to 10 days at elevated storage temperature) no damage found.

Test temperature: 100ºC for class 1 (resistance to permanent temperatures 80ºC);

Test temperature: 150ºC for class 3 (resistance to permanent temperatures 125ºC).

one

Claims (12)

1. Use of adhesive tape as tape enclosure for cables, so that the cables have a PVC-free coating, which includes a PVC-free support, to which at least one side a sensitive adhesive composition is applied to the pressure based on acrylate, so that the adhesive tape that glue the cables at a temperature of at least 100 ° C and during At least 240 hours, it does not damage the coating in any way. 2. Use of an adhesive tape according to claim 1, characterized in that it is coated with an adhesive composition such as pure acrylate, compound and / or mixture of the solution, as an aqueous system or as a molten metal of the melt. 3. Use according to claim 1, characterized in that a pressure sensitive adhesive composition based on molten acrylate metal is used. 4. Use according to one of the preceding claims, characterized in that a pressure sensitive adhesive composition having a K value of at least 20, in particular greater than 30, measured in a 1% solution in toluene is used at 25 ° C. 5. Use according to one of the preceding claims, characterized in that, the adhesive composition is obtained by concentrating a solution of said composition to give a system that can be treated as a molten metal. 6. Use according to one of the preceding claims, characterized in that, the solution of the adhesive composition contains 5-80% by weight, in particular 30-70% solvent. 7. Use according to one of the preceding claims, characterized in that conventional solvents are used, in particular low boiling temperature carbon hydrocarbons, ketones, alcohols and / or esters. 8. Use according to one of the preceding claims, characterized in that, one screw extruders, two screws or several screws with one, two or several degassing units are used. 9. Use according to one of the preceding claims, characterized in that the adhesive composition is crosslinked by chemical or thermal treatment, in particular by chemical ray treatment. 10. Use according to one of the preceding claims, characterized in that, the adhesive composition can be mixed with substances that can be activated by radiation and / or chemically or thermally, and / or have substances incorporated by polymerization, especially photoinitiators, in particular Benzoin derivatives 11. Use according to one of the preceding claims, characterized in that the self-adhesive compositions employed comprise copolymers of (meth) acrylic acid and its esters having 1-25 carbon atoms, maleic acid, fumaric acid, and / or itaconic and / or its esters, (meth) substituted acrylamides, maleic anhydride and other vinyl compounds, such as vinyl esters, especially vinyl acetate, vinyl alcohols and / or vinyl ethers. 12. Use according to one of the preceding claims, characterized in that, as a support, fabrics, knitwear, fleeces, sheets, paper, felt, foams or coextruded are used.